schematizer

Turn a generic, hierarchical netlist (JSON) into a KiCad schematic.

schematizer does the graphical half of EDA: it takes a tool-neutral netlist document and does all the drawing work — component placement, wire routing, and writing .kicad_sch files for a selected KiCad version (5–10). It is not tied to any particular front end: any tool that emits the netlist format can use it. SKiDL is the first such producer — SKiDL describes electrical interconnection in code and hands the netlist to schematizer — but the input is just JSON, so other generators work too.

The netlist document (produced by skidl.schematic_netlist.build_generic_netlist, or any equivalent emitter) embeds each component's symbol definition and carries layout hints — component mirror/rotate (symtx) and net stubbing (stub/netio). Because symbols are embedded, this tool needs no access to KiCad symbol libraries.

Install

pip install schematizer

Command-line use

# netlist.json -> KiCad 9 schematic files in ./out/
schematizer netlist.json --tool kicad9 -o out --top-name mydesign

Library use

import json
from schematizer import render

with open("netlist.json") as f:
    netlist = json.load(f)

render(netlist, tool="kicad9", filepath="out", top_name="mydesign")

render() also accepts a path to the JSON file directly.

How it fits with SKiDL

To the SKiDL end user nothing changes: Circuit.generate_schematic() builds the generic netlist internally and calls render() here. Because the seam is a plain JSON document, schematizer can be iterated and improved independently of SKiDL — and reused by any other front end that emits the same format.

Status

Self-contained. The placement/routing/writer engine is vendored under schematizer/engine, and the netlist is reconstructed into a lightweight intermediate representation (schematizer.ir: SchPart/SchPin/SchNet) that the engine consumes directly — no .kicad_sym re-parse, no KiCad library access, and no runtime dependency on skidl. The only runtime dependency is simp_sexp. The KiCad power-symbol library (for GND/rail nets) is vendored in schematizer/data.

Supported KiCad versions

--tool accepts kicad6 … kicad10, which share one modern S-expression writer (with a couple of KiCad-8 format toggles).

KiCad 5 is not supported and is rejected with an explanatory error. It needs the legacy EESCHEMA .sch format rather than .kicad_sch, and KiCad 5 libraries describe symbols in a different, non-s-expression form that the generic netlist does not carry.